In order to protect the string of a game racket from an excessive friction, the string holes of the game racket are provided with the string protecting casing of a nylon material. The string is generally made of a nylon material. As a result, the string can hardly slide in the string protecting casing when the string protecting casing is exerted on by a great pressure, thereby undermining the shock absorbing effect and the ball controlling effect of the game racket.
The U.S. Pat. Nos. 4,591,165 and 4,930,782 disclose respectively a game racket having a head frame provided on the outer edge thereof with a plurality of oval blocks. The string is wound such that the string passes the outer edge of each of the oval blocks before entering the inner side of the racket head frame. As a result, the strung surface of the game racket head is therefore capable of mitigating the impact of a ball making contact with the strung surface.
Such oval blocks as described above are generally defective in design in that the oval blocks are vulnerable to becoming detached from the head frame when the head frame or the strung surface is impacted severely, and that the oval blocks can not be effectively located when the game racket head is strung or when the string is broken.